Very much depends on what equipment you're currently using.
Generaly, if you want to track the stars you'll need a motor driven equatorial mount (preferably with a largish telescope to go with it! )
As for film speeds I wouldn't really try anything faster than 400 iso especially in B&W as the resolution and grain size will ruin much detail. If you are able to compensate for the earths rotation with an EQ mount and have quite dark skies then try to use a slower film speed like 100 or 200 iso.
Idealy, if you want to capture any of the planets or the moon you'll have much better results with a webcam like the Phillips ToUCam coupled to a telescope and stacking as many images together as you can.
If you're doing simple night sky shots but don't want the stars to trail (for instance, you want to show the consellations) you can build a simple barn-door mount, turned by hand, and use a fast normal or wide-angle lens, or with some practice, a short telephoto.
Also, try googling "Barn Door Mount" and "Amateur Astrophotography" or just "Astrophotography." You'll get lots of useful links.
I've seen this done, but I haven't done it myself. I'm planning on building one of these mounts myself, even have all the materials; I just haven't gotten around to it yet.
You can use slower speed films. I've read that a lot of people have used ASA 100 slide film with good results. Might be better to go with 200, 400, or even 800 at first, though, while you get the hang of using the thing. The longer exposure time with slow speed films can be tricky.